Physical Science : How a Torch Works

Physical Science : How a Torch Works

Hi, I’m Steve Jones and I’m going to explain
how a torch works. Well, I’ve got a diagram here of a torch. If I draw the circuit as
a circuit, a battery, remember a battery is the word for a group of cells. A battery,
the word battery just means a group. So, it’s a battery of cells. So this is a battery and
we’ve got here three one half volt cells, so you’ve got four point five volts. There
are three cells in series, inside the body of the torch. At this end you can see there
is a bulb. This is a filament lamp, that is it’s got the small thin piece of metal inside
which gets hot which provides the light. It’s got a screw thread which attaches it to this
side part here and this is part of the conducting part of the torch. So we end up with a circuit
that looks like this. We have a switch which we see here and we have a lamp. Now this is
a filament lamp usually represented in this way. And that is our circuit. It’s fairly
simple. It’s a cell or set of cells, a switch, and a lamp. Here the electricity will travel
through the filament, there’s the filament inside. So it comes in around the filament
and it comes in on this bottom part here which connects to the cell. So the circuit is shown
by, there’s the switch, there’s the lamp and here’s the cells and that is the circuit.
The additional thing that we find is next to the bulb there is a reflecting part, a
reflector here, to reflect the light this way and at the front a plastic lens. This
completes the torch. And obviously my torches never work and usually the reason is I don’t
use them very much. These batteries will run down very quickly if they’re not actually
used. So remember that’s how it works, so look after it and then it’ll work when you
want it to.

Comments (8)

  1. nice video , educative

  2. @TheMIKEMIKEMIKE11 neither can your english teacher by the looks of it

  3. @entitleddude Lol -nice one


  5. douche bag…

    I need to find science behind TORCHES NOT FUCKING FLASHLIGHTS

  6. I'm watching this in 2019

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